Conjugation of a smart polymer to doxorubicin through a pH-responsive bond for targeted drug delivery and improving drug loading on graphene oxide

Engineered nanoparticles as Selinexor drug delivery systems across the cell membrane and related signaling pathways in cancer cells

In the present work, molecular dynamics simulation is applied to evaluate the drug carrier efficiency of graphene oxide nanoflake (GONF) for loading of Selinexor (SXR) drug as well as the drug delivery by 2D material through the membrane in aqueous solution. In addition, to investigate the adsorption and penetration of drug-nanocarrier complex into the cell membrane, well-tempered metadynamics simulations and steered molecular dynamics (SMD) simulations were performed. Based on the obtained results, it is evident that intermolecular hydrogen bonds (HBs) and π-π interactions play a significant role in expediting the interaction between drug molecules and the graphene oxide (GO) nanosheet, ultimately resulting in the formation of a stable SXR-GO complex. The Lennard-Jones (L-J) energy value for the interaction of SXR with GONF is calculated to be approximately -98.85 kJ/mol. In the SXR-GONF complex system, the dominant interaction between SXR and GONF is attributed to the L-J term, resulting from the formation of a strong π-π interaction between the drug molecules and the substrate surface. Moreover, our simulations show by decreasing the distance of GONF with respect to cell membrane, the interaction energy of GONF-membrane significantly decrease to -1500 kJ/mol resulting in fast diffusion of SXR-GONF complex toward the bilayer surface that is favored opening the way to natural drug nanocapsule.

Synthesis and evaluation of amylose-mefenamic acid conjugates as colon-targeting prodrugs

Aim: Amide-linked amylose-based prodrugs were developed for colon-targeted release of mefenamic acid. Materials & methods: Activation of prodrug was studied spectrophotometrically, enzyme-linked immunosorbent assay appraised cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibition at different concentrations of the prodrug, the behavior of prodrug under physiological conditions was monitored by scanning electron microscopy. Results: Prodrug was poorly activated in the enzyme-free simulated gastric media and simulated intestinal media (SIM) but preincubation in pancreatin followed by treatment in aminopeptidase containing SIM led to a significant activation of prodrug. Conclusion: Amide-linked amylose-mefenamic acid conjugates showed a slow release in simulated gastric media and a controlled release in SIM with pancreatin playing an important role in drug release.

Material and Design Toolkit for Drug Delivery: State of the Art, Trends, and Challenges

The nanomaterial and related toolkit have promising applications for improving human health and well-being. Nanobased drug delivery systems use nanoscale materials as carriers to deliver therapeutic agents in a targeted and controlled manner, and they have shown potential to address issues associated with conventional drug delivery systems. They offer benefits for treating various illnesses by encapsulating or conjugating biological agents, chemotherapeutic drugs, and immunotherapeutic agents. The potential applications of this technology are vast; however, significant challenges exist to overcome such as safety issues, toxicity, efficacy, and insufficient capacity. This article discusses the latest developments in drug delivery systems, including drug release mechanisms, material toolkits, related design molecules, and parameters. The concluding section examines the limitations and provides insights into future possibilities.

Interaction of Graphene Oxide Particles and Dendrimers with Human Breast Cancer Cells by Real-Time Microscopy

Graphene oxide (GOX) has become attractive due to its unique physicochemical properties. This nanomaterial can associate with other dendrimers, making them more soluble and allowing better interaction with biomacromolecules. The present study aimed to investigate, by real-time microscopy, the behavior of human breast cancer cells exposed to particles of materials based on graphene oxide. The MCF-7 cell line was exposed to GOX, GOX associated with Polypropylenimine hexadecaamine Dendrimer, Generation 3.0-DAB-AM-16 (GOXD) and GOX associated with polypropyleneimine-PAMAM (GOXP) in the presence or absence of fetal bovine serum (FBS). GOX, GOXD and GOXP were taken up by the cells in clusters and then the clusters were fragmented into smaller ones inside the cells. Real-time microscopy showed that the presence of FBS in the culture medium could allow a more efficient internalization of graphene materials. After internalizing the materials, cells can redistribute the clumps to their daughter cells. In conclusion, the present study showed that the particles can adhere to the cell surface, favoring their internalization. The presence of FBS contributed to the formation of smaller aggregates of particles, avoiding the formation of large ones, and thus transmitted a more efficient internalization of the materials through the interaction of the particles with the cell membrane.

Density Functional Theory Interaction Study of a Polyethylene Glycol-Based Nanocomposite with Cephalexin Drug for the Elimination of Wound Infection

In this paper, density functional theory (DFT) simulations are used to evaluate the possible use of a graphene oxide-based poly(ethylene glycol) (GO/PEG) nanocomposite as a drug delivery substrate for cephalexin (CEX), an antibiotic drug employed to treat wound infection. First, the stable configuration of the PEGylated system was generated with a binding energy of -25.67 kcal/mol at 1.62 Å through Monte Carlo simulation and DFT calculation for a favorable adsorption site. The most stable configuration shows that PEG interacts with GO through hydrogen bonding of the oxygen atom on the hydroxyl group of PEG with the hydrogen atom of the carboxylic group on GO. Similarly, for the interaction of the CEX drug with the GO/PEG nanocomposite excipient system, the adsorption energies are computed after determining the optimal and thermodynamically favorable configuration. The nitrogen atom from the amine group of the drug binds with a hydrogen atom from the carboxylic group of the GO/PEG nanocomposite at 1.75 Å, with an adsorption energy of -36.17 kcal/mol, in the most stable drug-excipient system. Drug release for tissue regeneration at the predicted target cell is more rapid in moist conditions than in the gas phase. The solubility of the suggested drug in the aqueous media around the open wound is shown by the magnitude of the predicted solvation energy. The findings from this study theoretically validate the potential use of a GO/PEG nanocomposite for wound treatment application as a drug carrier for sustained release of the CEX drug.

PNIPAM/Hexakis as a thermosensitive drug delivery system for biomedical and pharmaceutical applications

Many technologies ranging from drug delivery approaches to tissue engineering purposes are beginning to benefit from the unique ability of “smart polymers.” As a special case, thermo-sensitive hydrogels have great potential, e.g. in actuators, microfluidics, sensors, or drug delivery systems. Here, the loading of Doxorubicin (DOX) with novel thermo-sensitive polymer N-isopropyl acrylamide (PNIPAM) and its copolymers are investigated in order to increase the Doxorubicin’s drug efficacy on the targeted tumor site. Therefore, a rational design accurate based on the use of classical molecular dynamics (MD) and well-tempered metadynamics simulations allows for predicting and understanding the behavior of thermo-responsive polymers in the loading of DOX on Hexakis nano-channel at 298 and 320 K. Furthermore, this work investigates the efficacy of this drug carrier for the release of DOX in response to stimuli like variations in temperature and changes in the physiological pH. The study concludes that the Hexakis–polymer composite is capable of adsorbing the DOX at neutral pH and by increasing the temperature of the simulated systems from 298 to 320 K, the strength of intermolecular attraction decreases. In addition, the obtained results of MD simulation revealed that the dominant interaction between DOX and Hexakis in the DOX/polymer/Hexakis systems is the Lennard–Jones (LJ) term due to the formation of strong π–π interaction between the adsorbate and substrate surface. Obtained results show that a higher aggregation of DMA chains around the Hexakis and the formation of stronger bonds with DOX. The results of the well-tempered metadynamics simulations revealed that the order of insertion of drug and polymer into the system is a determining factor on the fate of the adsorption/desorption process. Overall, our results explain the temperature-dependent behavior of the PNIPAM polymers and the suitability of the polymer–Hexakis carrier for Doxorubicin delivery.

Characteristics of Graphene Oxide for Gene Transfection and Controlled Release in Breast Cancer Cells

Functionalized graphene oxide (GO) nanoparticles are being increasingly employed for designing modern drug delivery systems because of their high degree of functionalization, high surface area with exceptional loading capacity, and tunable dimensions. With intelligent controlled release and gene silencing capability, GO is an effective nanocarrier that permits the targeted delivery of small drug molecules, antibodies, nucleic acids, and peptides to the liquid or solid tumor sites. However, the toxicity and biocompatibility of GO-based formulations should be evaluated, as these nanomaterials may introduce aggregations or may accumulate in normal tissues while targeting tumors or malignant cells. These side effects may potentially be impacted by the dosage, exposure time, flake size, shape, functional groups, and surface charges. In this review, the strategies to deliver the nucleic acid via the functionalization of GO flakes are summarized to describe the specific targeting of liquid and solid breast tumors. In addition, we describe the current approaches aimed at optimizing the controlled release towards a reduction in GO accumulation in non-specific tissues in terms of the cytotoxicity while maximizing the drug efficacy. Finally, the challenges and future research perspectives are briefly discussed.

Insights into glyphosate removal efficiency using a new 2D nanomaterial

Glyphosate (GLY) is a nonselective herbicide that has been widely used in agriculture for weed control. However, there are potential genetic, development and reproduction risks to humans and animals associated with exposure to GLY. Therefore, the removal of this type of environmental pollutants has become a significant challenge. Some of the two-dimensional nanomaterials, due to the characteristics of hydrophilic nature, abundant highly active surficial sites and, large specific surface area are showed high removal efficiency for a wide range of pollutants. The present study focused on the adsorption behavior of GLY on silicene nanosheets (SNS). In order to provide more detailed information about the adsorption mechanism of contaminants on the adsorbent's surface, molecular dynamics (MD) and well-tempered metadynamics simulations are performed. The MD results are demonstrated that the contribution of the L-J term in pollutant/adsorbent interactions is more than coulombic energy. Furthermore, the simulation results demonstrated the lowest total energy value for system-A (with the lowest pollutant concentration), while system-D (contains the highest concentration of GLY) had the most total energy (E _tot: -78.96 vs. -448.51 kJ mol^-1). The well-tempered metadynamics simulation is accomplished to find the free energy surface of the investigated systems. The free energy calculation for the SNS/GLY system indicates a stable point in which the distance of GLY from the SNS surface is 1.165 nm.